Acrylonitrile butadiene styrene (ABS) resins, thermoplastic resin compositions such as polycarbonate resins/ABS resins, or reinforced thermoplastic resin compositions prepared by reinforcing these thermoplastic resin compositions with inorganic fillers have been widely used as the housing materials of mobile devices such as laptop personal computers, tablet personal computers, mobile phones including smart phones, digital cameras, digital video movies, or the like. In general, as a method for producing a housing, an injection molding method in which the above resin compositions can be shaped freely to some extent has been employed.
In recent years, demands have increased for mobile devices to be thinner and more lightweight, and also to satisfactorily withstand the impacts and loads while being placed inside a bag or such containers, and to be capable of non-coating in terms of low cost. In order to satisfy these demands, the resin used for a housing has to have not only high rigidity, high strength and impact resistance, but also ability to mold a molded article having a high frame retardancy and good moldability.
Among the conventionally used resin materials for housings of mobile devices, molded articles composed of the ABS resins or polycarbonate resins/ABS resins that are not reinforced by inorganic fillers have low rigidity and could not meet the demands for thinning of mobile device housings in recent years.
Therefore, reinforced thermoplastic resin compositions to which inorganic fillers such as glass fibers or carbon fibers have been added, such that rigidity thereof is reinforced, have been used as resin materials for housings of mobile devices.
However, although molded articles composed of conventional reinforced thermoplastic resin compositions exhibit high rigidity, they are problematic as a housing material for mobile devices since they are brittle and easily broken.
As a method to overcome the problem, a method of blending an olefin wax having a carboxyl group with a fiber-reinforced polycarbonate resin has been proposed (Patent Document 1).
Further, for the purpose of improving the mechanical strength, a method of using glass fibers in which the surface thereof has been treated with a silane coupling agent and an epoxy resin (Patent Document 2), and a method of using carbon fibers converged by a nylon-based sizing agent (Patent Document 3) have been proposed.
Moreover, for the purpose of improving the plating appearance of the reinforced resin composition, a method of blending an inorganic filler of 0.1 to 60 parts by mass and a glycidyl ether unit-containing polymer have been proposed (Patent Document 4).